This the same idea that people have for CoD Zombies that Nikolai, Richtofen, Dempsey, and Takeo are stuck in purgatory fighting the living dead and at some points like in the Mob of the Dead its believed that they are stuck in Hell.

The idea from what I have been understanding is that Dr. Maxis is going to bring the dolls to life and that's when it all is going to really start because the story up to now has been a game that Samantha has been playing but in the real world there is a Zombie apocalypse going on and her father is trying to find a way to control it.